1. Field of the Invention
The present invention relates to locks. More particularly, the present invention relates to locks having both vertical pins and side pins, and to such locks having variable pin spacing.
2. The Prior Art
Conventional locks include a single set of split vertical tumbler pins, each pin disposed in a channel passing between the core and the barrel of the lock and spring-biased towards the center of the core. The channels are evenly spaced along the length of the core and the barrel of the lock. When a proper key is inserted in the lock, it pushes each pin outwardly to a position where the split in each vertical tumbler pin is aligned with the shear line between the core and the barrel of the lock, thus allowing the core to rotate within the barrel.
Another type of conventional lock includes a set of evenly-spaced vertical tumbler pins, each in disposed in a vertical shaft. This type of lock also includes a side bar attached to a set of side pins each disposed in a side shaft in the core. Each side shaft is axially aligned with a corresponding one of the vertical shafts containing the vertical tumbler pins. The side bar is biased in an axially-disposed channel in the barrel of the lock by springs associated with each side pin, thus preventing the core from rotating within the barrel. In such a lock, the vertical pins are not split, but each vertical tumbler pin has a side hole disposed in its side at a selected position along its length. The core cannot rotate within the barrel as long as the side bar is disposed in the channel.
When a properly-cut key is inserted in the lock, it moves each of the vertical tumbler pins to a position where the side hole is aligned with its corresponding side shaft in the core containing a side pin. Turning the properly-cut key causes the side bar to be pushed inward towards the center of the core because the attached side pins are thus allowed to enter the side holes in the vertical tumbler pins, thus allowing the side bar pin to move below the outer diameter of the core. If the hole in any vertical tumbler pin does not align correctly with the side bar pin, the side bar remains in the channel outside the outer diameter of the core and keeps the core from rotating. This key must cause this alignment between the tumbler, core, and side bar pin for all pins incorporated in the lock before the core will rotate to open the lock.
Conventional side bar locks use a single one-piece bar integrated with evenly-spaced side pins all disposed at the same angular position, resulting in a fixed distance between tumbler pins and their corresponding side pins. This fixed distance and fixed angular relationship between each tumbler pin and its corresponding side pin limits the number code combinations, which in turn limits the level of security available in this type of lock.